factory_test.go

- (Reported) factory now can 'nicely' fail on bad bccsp
  names
- (Part of debugging this problem) had test cases modifying
  default options. Hide default options behind a getter which
  returns a new instance every time, so that it does not get
  clobbered
- (Part of debugging this problem) SetupBCCSPKeystoreConfig
  should did not update bccsp config outside the function

Change-Id: I397a9e12908f5550ffc54e5277d950bf6428b571
Signed-off-by: Volodymyr Paprotski <vpaprots@ca.ibm.com>